Potential of Mie-Fluorescence-Raman Lidar to Profile Chlorophyll a Concentration in Inland Waters.

Vertical distribution of phytoplankton is crucial for assessing the trophic status and primary production in inland waters. However, there is sparse information about phytoplankton vertical distribution due to the lack of sufficient measurements. Here, we report, to the best of our knowledge, the first Mie-fluorescence-Raman lidar (MFRL) measurements of continuous chlorophyll a (Chl-a) profiles as well as their parametrization in inland water. The lidar-measured Chl-a during several experiments showed good agreement with the in situ data. A case study verified that MFRL had the potential to profile the Chl-a concentration. The results revealed that the maintenance of subsurface chlorophyll maxima (SCM) was influenced by light and nutrient inputs. Furthermore, inspired by the observations from MFRL, an SCM model built upon surface Chl-a concentration and euphotic layer depth was proposed with root mean square relative difference of 16.5% compared to MFRL observations, providing the possibility to map 3D Chl-a distribution in aquatic ecosystems by integrated active-passive remote sensing technology. Profiling and modeling Chl-a concentration with MFRL are expected to be of paramount importance for monitoring inland water ecosystems and environments.

Evaluating the Occurrence of Polystyrene Nanoparticles in Environmental Waters by Agglomeration with Alkylated Ferroferric Oxide Followed by Micropore Membrane Filtration Collection and Py-GC/MS Analysis.

Although nanoplastics (NPs) are recognized as emerging anthropogenic particulate pollutants, the occurrence of NPs in the environment is rarely reported, partly due to the lack of sensitive methods for the concentration and detection of NPs. Herein, we present an efficient method for enriching NPs of different compositions and various sizes. Alkylated ferroferric oxide (Fe3O4) particles were prepared as adsorbents for highly efficient capture of NPs in environmental waters, and the formed large Fe3O4-NP agglomerates were separated by membrane filtration. Detection limits of 0.02-0.03 µg/L were obtained for polystyrene (PS) and poly(methyl methacrylate) (PMMA) NPs by detection with pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS). When analyzing real water samples from different sources, it is remarkable that PS NPs were detected in 11 out of 15 samples with concentrations ranging from <0.07 to 0.73 µg/L, while PMMA were not detected. The wide detection of PS NPs in our study confirms the previous speculation that NPs may be ubiquitous in the environmental waters. The accurate quantification of PS NPs in environmental waters make it possible to monitor the pollution status of NPs in aquatic systems and evaluate their potential risks.

Nootkatone alleviates rotenone-induced Parkinson's disease symptoms through activation of the PI3K/Akt signaling pathway.

Parkinson's disease (PD) is the second most common neurodegenerative disease worldwide. Nootkatone (NKT) has been shown to have neuroprotective, anti-inflammatory, and antioxidant effects and in this study, we systematically studied the efficacy and mechanism of action of NKT in rotenone (ROT)-induced PD rats. Firstly, through behavioral experiments and brain tissue staining, we found that NKT alleviated behavioral dysfunction and protected dopaminergic neurons associated with ROT-induced PD rats. Next, target prediction, protein-protein interaction (PPI), Gene Ontology (GO), and pathway enrichment analyses were used to obtain potential targets, specific biological processes, and molecular mechanisms of NKT for the potential treatment of PD. Furthermore, we also applied molecular docking to predict the binding capacity of NKT and related targets. Additionally, in vivo experiments confirmed that NKT could inhibit the expression of Mitogen-activated protein kinase 3 (MAPK3) by activating the PI3K/Akt signaling pathway, reducing neuroinflammation, and ultimately ameliorating ROT-induced PD symptoms. Taken together, the results of the study provide a clear explanation for the remission of PD symptoms by NKT, suggesting that it may be a promising candidate for the treatment of PD.

Sequential Isolation of Microplastics and Nanoplastics in Environmental Waters by Membrane Filtration, Followed by Cloud-Point Extraction.

Respective detection of microplastics (MPs) and nanoplastics (NPs) is of great importance for their different environmental behaviors and toxicities. Using spherical polystyrene (PS) and poly(methyl methacrylate) (PMMA) plastics as models, the efficiency for sequential isolation of MPs and NPs by membrane filtration and cloud-point extraction was evaluated. After filtering through a glass membrane (1 µm pore size), over 90.7% of MPs were trapped on the membrane, whereas above 93.0% of NPs remained in the filtrate. The collected MPs together with the glass membrane were frozen in liquid nitrogen, ground, and suspended in water (1 mL) and subjected to pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) determination. The NPs in the filtrate were concentrated by cloud-point extraction, heated at 190 °C to degrade the extractant, and then determined by Py-GC/MS. For MPs and NPs spiked in pure water, the method detection limits are in the range of 0.05-1.9 µg/L. The proposed method is applied to analyze four real water samples, with the detection of 1.6-7.6 µg/L PS MPs and 0.6 µg/L PMMA MPs in three samples, and spiked recoveries of 75.0-102% for MPs and 67.8-87.2% for NPs. Our method offers a novel sample pretreatment approach for the respective determination of MPs and NPs.

Mutasynthesis of Antibacterial Halogenated Actinomycin Analogues.

Through precursor-directed biosynthesis, feeding halogenated (F-, Cl-, Br-, I-) or methoxy-substituted 4-methyl-3-hydroxyanthranilic acid (4-MHA) analogues to the acnGHLM-deleted mutant strain of Streptomyces costaricanus SCSIO ZS0073 led to the production of ten new actinomycin analogues (4-13). Several of the actinomycin congeners displayed impressive antimicrobial activities, with MIC values spanning 0.06-64 µg/mL to clinically derived antibiotic resistant pathogens, including Staphylococcus aureus, Enterococcus faecium, and Candida albicans, with low cytotoxicity.

[Spectrum-effect relationship of the blood-activating efficacy of Notoginseng Radix et Rhizoma].

This study aims to establish the high-performance liquid chromatography(HPLC) fingerprints of different batches of Notoginseng Radix et Rhizoma, determine their pharmacodynamic indexes of promoting blood circulation, and explore the spectrum-effect relationship between the chemical components of Notoginseng Radix et Rhizoma and the efficacy of promoting blood circulation. Firstly, the HPLC fingerprints of different batches of Notoginseng Radix et Rhizoma were established. Then, the pharmacodynamic indexes were determined after the capillary coagulation experiment and the cerebral ischemia-reperfusion in rats, including capillary coagulation time, percentage of cerebral ischemic area, cerebral water loss rate, and brain-body index. Afterward, the partial least-squares method was used to explore the spectrum-effect relationship between the chemical components of Notoginseng Radix et Rhizoma and the pharmacodynamic indexes. The results showed that this study successfully established the HPLC fingerprints of different batches of Notoginseng Radix et Rhizoma, found 23 common peaks, and identified 12 of them, all of which were saponins. The method was proved stable and reliable. Both the capillary coagulation experiment and the middle cerebral artery occlusion(MCAO)-induced cerebral ischemia-reperfusion experiment on rats revealed that there were obvious differences in the pharmacodynamic indexes of different batches of Notoginseng Radix et Rhizoma. The relationships between 23 common components of Notoginseng Radix et Rhizoma in different batches and the pharmacodynamic indexes were discussed by means of spectrum-effect correlation analysis, of which 17 components had positive effects while 6 components had negative effects on the pharmacodynamic indexes. This study provides a certain reference basis for the clinical rational use and quality control of Notoginseng Radix et Rhizoma.

[Spectrum-effect relationship of hemostatic effects of Notoginseng Radix et Rhizoma with different commodity specifications].

This article aims to establish the fingerprints, determine the hemostatic pharmacodynamic indicators, and explore the spectrum-effect relationship of Notoginseng Radix et Rhizoma in 12 different specifications. Firstly, HPLC and liquid chromatography-mass spectrometry(LC-MS) were employed to establish the fingerprints of Notoginseng Radix et Rhizoma. The rat plasma recalcification experiment and the rat gastric bleeding experiment were conducted to determine the pharmacodynamic indicators, including plasma recalcification time(PRT), thrombin time(TT), prothrombin time(PT), and activated partial thromboplastin time(APTT). Afterwards, the partial least squares method was employed to explore the spectrum-effect relationship of Notoginseng Radix et Rhizoma in different specifications. Twenty-six common peaks were detected in the HPLC fingerprints of different specifications of Notoginseng Radix et Rhizoma, and 11 out of the 26 common peaks represented saponins. The content of dencichine was determined by LC-MS. The rat experiments showed that the pharmacodynamic indicators were significantly different among different specifications of Notoginseng Radix et Rhizoma. The spectrum-effect relationship was explored between 27 common components and pharmacodynamic indicators. Among them, 16 components had positive effects on the pharmacodynamic indicators of Notoginseng Radix et Rhizoma, and 11 exerted negative effects. This study provides a basis for the precision medication and quality control of Notoginseng Radix et Rhizoma.

Air-Seawater Gas Exchange and Dry Deposition of Chlorinated Paraffins in a Typical Inner Sea (Liaodong Bay), North China.

As a group of new persistent organic pollutants, short-chain chlorinated paraffins (SCCPs) and medium-chain CP (MCCPs) have attracted extensive worldwide interest in recent years. However, the data regarding to the environmental behavior, especially in atmospheric transfer and air-seawater exchange, are still sparse. In this study, seasonal marine boundary layer air and seawater samples were collected from Chinese Bohai sea and a fugacity model was built to evaluate the air-seawater diffusion and deposition flux of CPs. Generally, the total CP levels in atmosphere and seawater samples in summer were higher than those in spring, and CPs existed mostly in the gaseous phase in air and the dissolved phase in seawater. For SCCPs, C10 and C11 components were the most abundant homologue groups. For MCCPs, the C14 homologue dominated in the particle phase of atmosphere and particulate phase of seawater. The logarithmic fugacity ratios (log fa/ fw) of higher chlorinated congeners (Cl8 to Cl10: 0.71 to 1.32 in May and 1.38 to 2.29 in August) indicated that net deposition was the predominant process, whereas lower chlorinated congeners, especially Cl5 homologue groups in August, showed a trend of net volitization (log  fa/ fw < -0.5). The results of diffusion and dry deposition fluxes indicated that air-seawater gas exchange of CPs was significantly higher than dry deposition in the sampling areas.

Characterization of Brominated Disinfection Byproducts Formed During the Chlorination of Aquaculture Seawater.

Although brominated disinfection byproducts (Br-DBPs) have been reported to form from reactions between bromide, dissolved organic matter (DOM), and disinfectants, their formation during the disinfection of aquaculture seawater via chlorination has been rarely studied. Herein, after 5 days of disinfection of raw aquaculture seawater samples with sodium dichloroisocyanurate (NaDDC), trichloroisocyanuric acid (TCCA) and chlorine dioxide (ClO2), 181, 179, and 37 Br-DBPs were characterized by ultrahigh-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Sunlight irradiation of the chlorinated aquaculture seawater with TCCA and NaDDC was found to reduce the formation of Br-DBPs, possibly due to the photodegradation of the important HBrO/HClO intermediate and the degradation of formed Br-DBPs. The formation of Br-DBPs chlorinated by ClO2 increased under sunlight irradiation. The number of Br-DBPs formed during chlorination processes agreed well with the total organic bromine (TOBr) content measured by inductively coupled plasma mass spectrometry (ICP-MS). Most of the Br-DBPs were highly unsaturated and phenolic compounds, which were primarily generated through electrophilic substitution by bromine coupled with other reactions. In addition, some emerging aromatic Br-DBPs with high relative intensities were also assigned, and these compounds might be highly lipophilic and could potentially accumulate in marine organisms. Our findings call for further focus on and investigation of the Br-DBPs produced in chlorinated aquaculture seawater.

Occurrence and bioaccumulation of polybrominated diphenyl ethers in sediments and paddy ecosystems of Liaohe River Basin, northeast China.

Concentrations of 16 polybrominated diphenyl ether (PBDE) congeners were measured in river sediments, paddy soils and three species of paddy-field organisms (crab, loach and carp) collected from the Liaohe River Basin, northeastern China. The total contents of PBDEs (∑16PBDEs) in sediments and paddy soils were in the ranges of 273.4-3246.3pg/g dry weight (dw), and 192.1-1783.8pg/gdw, respectively. BDE 209 was the dominant congener both in sediments and paddy soils. The concentrations of ∑16PBDEs in sediments were significantly higher than those in the adjacent paddy soils, indicating a potential transport of PBDEs from river to paddy ecosystems via river water irrigation. The biota-soil accumulation factor (BSAF) was calculated as the ratio between the lipid-normalized concentration in paddy-field organisms and the total organic carbon-normalized concentration in paddy soil. The average BSAF values of ∑15PBDEs followed the sequence of crab (3.6)>loach (3.3)>carp (2.1). BDE 154 had the highest BSAF value, and a parabolic trend between BSAF values of individual PBDE congeners and their logKOW values was observed. In view of the fact that crab had the larger BSAF value and higher lipid content, the ecological risk and health risk for crab cultivation in paddy fields should be of particular concern.

Geographical distribution and risk assessment of persistent organic pollutants in golden threads (Nemipterus virgatus) from the northern South China Sea.

Fish are often used as good bioindicators to monitor the occurrence of persistent organic pollutants (POPs) on different scales in recent years. Forty-five golden threads (Nemipterus virgatus) were collected from six sampling sites in the northern South China Sea (SCS) to investigate the geographical distribution of polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane and its metabolites (DDTs). Concentrations of PBDEs, PCBs, and DDTs ranged from 1.3-36.0, 2.3-76.5, 8.3-228 ng/g lipid weight, respectively. The highest PBDEs and DDTs concentrations were found in golden threads from Shantou, owing to the intensive electronic waste recycling activities and rapid development of agriculture. Samples from Haikou had the highest levels of PCBs, probably due to the existence of many shipbuilding yards in the past years. The concentrations of PBDEs and PCBs were found in a decreasing trend from east to west and from north to south, while DDTs concentrations had no obvious trend in the distribution. PCBs were the most prevalent contaminants in Xiamen and Yangjiang, while DDTs were the dominant compounds at the other four sampling sites. Different profiles of POPs at each sampling site may attribute to different pollution sources in the northern SCS. Ratios of (DDD + DDE)/DDTs in golden threads suggested the probability of fresh input of DDT in the northern SCS. The estimated daily intakes of PBDEs, PCBs and DDTs were 0.030-0.069, 0.167-0.258 and 0.105-1.88 ng/kg/day, respectively, which were significantly lower than the acceptable daily intake, suggesting that consumption of golden threads from the northern SCS would not subject the residents in the coastal areas of SCS to significant health risk.

Distribution characteristics and indicator significance of Dechloranes in multi-matrices at Ny-Ålesund in the Arctic.

In recent years, Dechloranes have been widely detected in the environment around the world. However, understanding and knowledge of Dechloranes in remote regions, such as the Arctic, remain lacking. Therefore, the concentrations of 5 Dechloranes in surface seawater, sediment, soil, moss, and dung collected from Ny-Ålesund in the Arctic were measured with the concentrations 93 pg/L, 342, 325, 1.4, and 258 pg/g, respectively, which were much lower than those in Asian and European regions. The mean ratios of anti-Dechlorane Plus (DP) to total DP (ƒanti) in seawater, sediment, soil, moss, dung, and atmospheric samples were 0.36, 0.21, 0.18, 0.27, 0.66, and 0.43, respectively. Results suggested that the main source of DP in seawater, sediment, soil, and moss was long-range atmospheric transport. However, the ratio identified in dung was different, for which the migration behavior of the organism is probably the main source of DP.

Bioaccumulation and trophic transfer of short chain chlorinated paraffins in a marine food web from Liaodong Bay, North China.

Short chain chlorinated paraffins (SCCPs) are under the evaluation for inclusion into the Stockholm Convention on persistent organic pollutants. However, information on their bioconcentration and biomagnification in marine ecosystems is unavailable, limiting the evaluation of their ecological risks. In this study, seawater, sediment, zooplankton, invertebrates, and fishes collected from Liaodong Bay, Bohai Sea, North China were analyzed to investigate the residual level, congener group profile, bioaccumulation, and trophic transfer of SCCPs in a marine food web. The total concentrations of SCCPs ranged from 4.1 to 13.1 ng L(-1) in seawater, 65 to 541 ng g(-1) (dw) in sediment, and 86 to 4400 ng g(-1) (ww) in organisms. Correspondence analysis indicated the relative enrichment of C10Cl5 and C11Cl5 formula groups in most aquatic organisms. Both the logarithm bioaccumulation factors (log BAFs: 4.1-6.7) and biota-sediment accumulation factors (BSAFs: 0.1-7.3) of individual congeners implied the bioaccumulation of SCCPs. The trophic magnification factor (TMF) of ∑SCCPs was determined to be 2.38 in the zooplankton-shrimp-fish food web, indicating biomagnification potential of SCCPs in the marine ecosystem. The TMF values of individual congener groups significantly correlated with their log KOW values.

Benzotriazole ultraviolet absorbents in surface waters and sediments of the Bohai Sea and North Yellow Sea: Spatial trends and influencing factors.

Benzotriazole ultraviolet absorbents (BUAs) of emerging concern were recently monitored in seawater and sediments from the Bohai Sea (BS) and North Yellow Sea (NYS), which are impacted by human activities, to elucidate their regional occurrence patterns, phase distributions, and contamination profiles. Although environmental variables such as sedimentary organic carbon, particle size, and salinity, as well as hydrological conditions, affected the environmental occurrence of BUAs in the BS and NYS, the source dependence of BUA distributions associated with urban impacts and riverine inputs was highlighted. Substantial spatial variability in the composition patterns and contamination profiles of BUAs identified through correlation and principal component analyses were likely caused by region-specific sources and characteristics. The distribution of target BUAs between the sediment and seawater phases showed no dependence on the octanol-water partition coefficient (KOW) but exhibited marked spatial variations. The diversity of BUA sorption behaviors was further explained by the total organic carbon (TOC)-normalized distribution coefficient (KTOC). Classic logKTOC-logKOW linear relationships accurately predicted the phase distributions of UV-326, UV-328, and UV-234, but deviations were found for lighter and heavier BUAs, possibly due to the influences of physical disturbance and microparticle binding.

Community-level risk assessments on organophosphate esters in the sediments from the Bohai Sea of China based on multimodal species sensitivity distributions coupled with the equilibrium partitioning method.

Organophosphate esters (OPEs), increasingly used as alternatives to brominated flame retardants, are ubiquitous in the global aquatic environment. Despite their potential toxicological impact on ecosystems, community-level risk assessments for OPEs in sediments remain scarce. This study investigated OPE occurrences and composition characteristics in the Bohai Sea's sediments and appraised both individual and joint ecological risks posed by characteristic OPE homologs using ten commonly used species sensitivity distribution (SSD) models, integrating acute-to-chronic conversion and phase equilibrium partitioning. OPEs were detected across all sediment samples, with total concentrations ranging from 0.213 ng/g dry weight (dw) to 91.1 ng/g dw. The predominant congeners included tri-n-butyl phosphate (TnBP), triisobutyl phosphate (TiBP), tri(2-ethylhexyl) phosphate, tri(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP), tris(1, 3-dichloro-2-propyl) phosphate (TDCIPP), and triphenylphosphine oxide. Best-fit SSD models varied among TnBP, TiBP, TCEP, TCPP, and TDCIPP, demonstrating Sigmoid, Burr III, Sigmoid, Burr III, and Burr III, respectively. The same parametric model demonstrated variability in the fitting process for different OPE congeners, which also happened to the fitting results of ten parametric models for the same specific characteristic congener, underscoring the necessity of employing multiple models for precise community-level risk assessments. Hazard concentrations for a 5% cumulative probability were 0.116 mg/L, 2.88 mg/L, 1.30 mg/L, 1.44 mg/L, and 1.85 mg/L for each respective congener. The resulting risk quotients (RQ) and overall hazard index (HI) were selected as criteria to assess the individual and joint ecological risks of OPEs in sediments from the Bohai Sea, respectively. RQ and HI were both below 0.1, indicating a low risk to the local ecosystems. Multi-model SSD analysis could provide refined data for community-level risk evaluation, offering valuable insights for the development of evidence-based environmental standards and pollution control strategies.

XBAT31 regulates reproductive thermotolerance through controlling the accumulation of HSFB2a/B2b under heat stress conditions.

Heat shock transcription factors (HSFs) play a crucial role in heat stress tolerance in vegetative tissues. However, their involvement in reproductive tissues and their post-translational modifications are not well understood. In this study, we identify the E3 ligase XB3 ORTHOLOG 1 IN ARABIDOPSIS THALIANA (XBAT31) as a key player in the ubiquitination and degradation of HSFB2a/B2b. Our results show that the xbat31 mutant exhibits a higher percentage of unfertile siliques and decreased expression of HSPs in flowers under heat stress conditions compared to the wild type. Conversely, the hsfb2a hsfb2b double mutant displays improved reproductive thermotolerance. We find that XBAT31 interacts with HSFB2a/B2b and mediates their ubiquitination. Furthermore, HSFB2a/B2b ubiquitination is reduced in the xbat31-1 mutant, resulting in higher accumulation of HSFB2a/B2b in flowers under heat stress conditions. Overexpression of HSFB2a or HSFB2b leads to an increase in unfertile siliques under heat stress conditions. Thus, our results dissect the important role of the XBAT31-HSFB2a/B2b module in conferring reproductive thermotolerance in plants.

Different responses of marine microalgae Phaeodactylum tricornutum upon exposures to WAF and CEWAF of crude oil: A case study coupled with stable isotopic signatures.

Increasing use of chemical dispersants for oil spills highlights the need to understand their adverse effects on marine microalgae and nutrient assimilation because the toxic components of crude oil can be more bioavailable. We employed the crude oil water-accommodated fraction (WAF) and chemically enhanced WAF (CEWAF) to compare different responses in marine microalgae (Phaeodactylum tricornutum) coupled with stable isotopic signatures. The concentration and proportion of high-molecular-weight polycyclic aromatic hydrocarbons (HMW PAHs), which are key toxic components in crude oil, increased after dispersant addition. CEWAF exposure caused higher percent growth inhibition and a lower chlorophyll-a level of microalgae than those after WAF exposure. Compared with WAF exposure, CEWAF led to an enhancement in the self-defense mechanism of P. tricornutum, accompanied by an increased content of extracellular polymeric substances. 13C-depletion and carbon assimilation were altered in P. tricornutum, suggesting more HMW PAHs could be utilized as carbon sources by microalgae under CEWAF. CEWAF had no significant effects on the isotopic fractionation or assimilation of nitrogen in P. tricornutum. Our study unveiled the impact on the growth, physiological response, and nutrient assimilation of microalgae upon WAF and CEWAF exposures. Our data provide new insights into the ecological effects of dispersant applications for coastal oil spills.

Source and sequestration of sediment organic carbon from different elevation zones in estuarine wetland, North China.

Estuarine wetland plays an important role in regulating global carbon cycle due to high terrestrial carbon input and burial. However, it is unclear how the source and sequestration of sediment organic carbon (SOC) in estuarine wetlands changes under the anthropogenic impact in the past century. In this study, combining parameters of TOC/TN ratios, δ13C, δ15N and 210Pb-chronology, temporal trends of SOC source and sequestration flux in Liaohe estuarine wetland were studied. The results showed that the source of organic carbon in Liaohe estuarine wetland was dominated by terrestrial input (contribution >60 %). Due to vegetation, TOC in shallow reed marsh was significantly higher than that of bare beach and subtidal flat. Affected by elevation, the sediment mass accumulation rate (MAR, kg·m-2·yr-1) showed differences in reed marsh (C1), bare beach (C2) and subtidal flat (C3), which were 6.57, 13.56 and 13.25 respectively in the past century. MAR fluctuated over time, it showed an overall increasing trend, especially since the 1980s. Correspondingly, the sequestration flux of SOC (SF-SOC, g·m-2·yr-1) showed an overall increasing trend with average of 82.84 (reed marsh), 151.93 (bare beach) and 123.71 (subtidal flat). Comparing to TOC, the higher MAR had a more distinct effect on carbon sequestration in Liaohe estuarine wetland. The difference in sedimentation rate and carbon sequestration are linked to the changes in sediment flux of riverine input and land utilization in the catchment area due to human activities in recent decades, including the construction of reservoirs, dams and local ditch wharf.

Investigating the presence of organophosphate esters in sediments from a typical fishing port agglomeration in Dalian, North China.

The presence of 14 organophosphate esters (OPEs) in surface sediments from a typical fishing port agglomeration in Dalian, North China was investigated for the first time. Tris(2-ethylhexyl) phosphate (TEHP), triphenylphosphine oxide (TPPO), and tris(2-chloroethyl) phosphate (TCEP) dominated 12 detectable OPEs (∑OPEs), with concentrations ranging widely from 0.56 to 352 ng/g (dry weight basis). The ∑OPE levels in sediments varied significantly across fishing harbors of various grades, and within the same grade, highlighting uneven distribution of OPE sources and inputs to harbors. The first- and second-class fishing harbors had higher geometric mean of ∑OPE contents compared to center and natural harbors, reflecting higher OPE pollution in these areas. Although there were significant correlations among the OPE congeners with high detection frequencies, the composition patterns of sediment OPEs varied considerably among fishing ports. The sediments in the center and first-class harbors had higher abundance of non-chlorinated OPEs (non-Cl-OPEs), suggesting heterogeneity in source strength and pollution characteristics of Cl- and non-Cl-OPEs in fishing ports. The distribution of OPEs in sediments was weakly associated with sediment organic carbon, but not socioeconomic variables, indicating complex controlling factors of their distributions in port sediments. The ecological risks of sediment OPEs were evaluated, and while OPE accumulations ranged broadly (7-684 ng/cm2), exposure hazards were negligible. The sediments in first- and second-class fishing harbors, which had greater OPE accumulation, were identified as reservoirs of OPEs in port aquatic environments.

Polycyclic aromatic hydrocarbons in Fildes Peninsula, maritime Antarctica: Effects of human disturbance.

This study provides the first data on the distribution, sources, and transport dynamics of polycyclic aromatic hydrocarbons (PAHs) in Fildes Peninsula, Antarctica via summertime analyses of lakes, seawater, snow, and air in 2013. Relatively high PAH levels and similar composition profiles (dominance of two- and three-ring PAHs) in the investigated marine and terrestrial environmental matrices were found, indicating substantial primary emissions of petrogenic PAHs. This result was corroborated by nonequilibrium partitioning of atmospheric PAHs caused by release of anthropically-derived lighter PAHs and air mass movement trajectories mainly originated from the Antarctic marginal seas. Notable geographical disparities of PAH pollution in the various types of samples consistently suggested impacts of station-related activities, rather than long-range atmospheric transport, on PAHs in Fildes Peninsula. The lack for temperature dependence for gas-phase concentrations and various molecular diagnostic ratios of atmospheric PAHs demonstrated that the impact of local anthropogenic inputs on air PAH variability supersedes the re-emission effect. The derived air-water and air-snow exchanges of PAHs in this remote region indicated a disequilibrium state, partially associated with intense local emissions of PAHs. PAH outgassing from, and absorption into, lake and marine waters were both observed, probably due to differences in anthropogenic influences among sites, while the net deposition of gaseous PAHs into snow prevailed. The results of this study shed lights on the major importance of native anthropogenic sources in the footprint and fate of PAHs in the Fildes Peninsula, which merits further monitoring.